Automatic turning machine

ABSTRACT

An automatic turning machine which employs two discrete turning units and a transfer mechanism serving to deliver semifinished workpieces from the first unit to the second unit. The first unit employs a rotary work spindle which cooperates with several cross slides and, if necessary, with a turret or tool spindle for tools whereby the tools which are held by the cross slides and/or turret and tool slide treat the workpiece while the latter rotates with the work spindle. The second unit employs an indexible carrier with several sets of equidistant jaws which transport workpieces, received from the work spindle by way of the transfer mechanism, past several working stations at each of which a workpiece held by the respective jaws can be treated by one or more rotary tools which are mounted in tool spindles forming part of assemblies mounted for movement radially, in parallelism with or at another angle relative to the axis of the carrier.

Foli et al.

States ate'rti [1 1 AUTOMATIC TURNING MACHINE [58] FieldofSearch,.....29/38 A, 38 B, 38 C, 563, 29/564, 27 R, 27 A, 27 C, 33 J,36, 37 R, 37 A; 408/71 [4 1 Feb. 26, 1974 FOREIGN PATENTS ORAPPLICATIONS 1,259,674 1/1968 Germany 29/37 A Primary Examiner-FrancisS. Husar Attorney, Agent, or Firm-Michael S. Striker 57 ABSTRACT Anautomatic turning machine which employs two discrete turning units and atransfer mechanism serving to deliver semifinished workpieces from thefirst unit to the second unit. The first unit employs a rotary workspindle which cooperates with several cross slides and, if necessary,with a turret or tool spindle for tools whereby the tools which are heldby the cross slides and/or turret and tool slide treat the workpiecewhile the latter rotates with the work spindle. The second unit employsan indexible carrier with several sets of equidistant jaws whichtransport workpieces, received from the work spindle by way of thetransfer mechanism, past several working stations at each of which aworkpiece held by the respective jaws can be [56] References cuedtreated by one or more rotary tools which are UNITED STATES PATENTSmounted in tool spindles forming part of assemblies 2,087,109 7/1937 Lee29/36 mounted for movement radially, in parallelism with or 3,689,9659/1972 Bertoglio 408/71 at another angle relative to the axis of thecarrier. 3,683,724 8/1972 Crane 29/38 B 2,080,157 5 1937 Yager et al.29/38 A 15 Clams, 5 Drawing Flgures 3,200,472 8/l965 Kohring et al.29/38 B 7 h l. l

PAIENTEDFEBZBIW 3793707 SHEET 1 (IF 3 PATENTEB FEB26 I974 SHEET 2 (1F 3Fig. 2

PATENTED FEBZSIHH sum 3 or 3 1 AUTOMATIC TURNING MACHINE BACKGROUND OFTHE INVENTION The present invention relates to turning machines ingeneral, and more particularly to improvements in automatic turningmachines.

Certain types of presently known turning machines employ a rotary workspindle and one or more slides for tools which are fed against aworkpiece while the latter is held by and rotates with the spindle. Suchturning machines are capable of treating workpieces with a high degreeof precision, especially as concerns the treatment of cylindricalsurfaces. If a thus treated workpiece thereupon requires additionaltreatment, for example, the machining of its internal or externalsurfaces at the front end, the turning machine employs tool spindles andtool turrets; the tools carried by such spindles or turrets are broughtinto contact with a workpiece in the work spindle one after the other.Slotting, back-drilling and similar operations are carried out byresorting to auxiliary equipment which can be used in combination withthework spindle. The formation of radial or diametral slots or the likeis performed while the workpiece is at a standstill. The just mentionedauxiliary equipment may comprise gripper means serving to engage aworkpiece which has been separated from the bar and to introduce thefreshly separated workpiece into a suitable chuck which is thereupontransferred to one or more treating stations. The output of such turningmachines is relatively low.

It is also known to provide a turning machine with a carrier in the formof a turntable or turret whose periphery carries a plurality ofequidistant work engaging means in the form of pairwise arranged jaws orclaws which can releasably hold workpieces during transport toward andduring treatment at a plurality of working stations. The just describedtypes of turning machines employ rotary tools which can be fed intoengagement with workpieces at the respective working stations, whereby aworkpiece which dwells at a particular station can be simultaneouslytreated by two or more rotary tools. An advantage of such turningmachines is that their output is much higher than the output of machines employing a rotary work spindle. However, the quality of work isless satisfactory, mainly because a thus produced article is likely torun out of true. The high output is attributable to the fact that themachine can treat a large number of workpieces at the same time, i.e.,during each dwell between successive indexing movements of the turntableor turret, and also to the possibility of simultaneously treating anygiven workpiece by two or more rotary tools.

SUMMARY OF THE INVENTION An object of the invention is to provide anovel and improved turning machine whose versatility far exceeds theversatility of presently known machines, which can be operated in afully automatic way, which can finish at least some portions ofworkpieces with a very high degree of accuracy, and which can be usedfor the treatment of a wide variety of metallic or other workpieces.

Another object of the invention is to provide a tuming machine whichexhibits all advantages of the aforediscussed conventional machines butavoids their drawbacks.

A further object of the invention is to provide a turning machine whichcan finish workpieces with a high degree of precision and can turn outlarge numbers of workpieces per unit of time, which can be rapidly andconveniently converted for the treatment of different types and/or sizesof articles, and which can be used as a superior substitute for severalconventional turning machines.

An additional object of the invention is to provide the improved turningmachine with novel and improved transfer means for transportingsemifinished workpieces between different types of work retaining means.

The improved turning machine comprises a first turning unit having arotary work spindle and at least one tool supporting slide whichcooperates with the work spindle so that a workpiece which is held androtated by the spindle can be treated by a tool of the slide with a highdegree of accuracy, a second turning unit having a carrier in the formof an indexible turret or turntable for a plurality of equidistant pairsof jaws or analogous work engaging means, means for indexing the carrierso as to move workpieces held by the work engaging means between aplurality of successive stations, and at least one tool supportingassembly provided at at least one of the stations and cooperating withthe carrier so that a tool held by the assembly can treat a workpiecewhich is held by the respective work engaging means at the correspondingstation, and transfer means'which is or can be rendered operative totransport workpieces between the work spindle and a selected station. Inaccordance with a presently preferred embodiment, the transfer means isdesigned to transport workpieces from the work spindle to the workengaging means at the selected station so that a workpiece whosetreatment in-the first unit has been completed can be subjected to oneor more additional treatments during transport by the carrier.

The turning machine is preferably further provided with control meanswhich synchronizes the operation of the first unit with the operation ofthe second unit. Also, the carrier is preferably indexible about an axiswhich can be horizontal and isparallel with the axis of the workspindle. I

The novel features which are considered as characteristic of theinvention are set forth in particular in the appended claims. Theimproved turning machine itself, however, both as to its constructionand its mode of operation, together with additional features andadvantages thereof, will be best .understood upon per usal of thefollowing. detailed description of certain specific embodiments withreference to the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a side elevational view of aturning machine v which embodies the invention;

FIG. 2 is a front elevational view as seen in the direction of arrow Ashown in FIG. 1, with certain parts omitted;

FIG. 3 is an enlarged fragmentary view as seen in the direction of arrowB shown in FIG. 1, with the cover for the control mechanism removed;

FIG. 4 is an enlarged view of the transfer device in the turning machineof FIG. I, with the transfer device shown in two different positions;and

FIG. 5 is a side elevational view of the structure shown in FIG. 4, withcertain parts of the transfer device illustrated in section.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring first to FIGS. 1 to3, there is shown an automatic turning machine comprising a frame whichis provided with an upwardly extending portion 12 serving as a base fora spindle box 14. The latter supports a rotary work spindle 16 which isrotatable about a horizontal axis. The work spindle 16 is assumed to behollow so that it can accommodate an axially movable bar (not shown) thefront end portion of which extends forwardly beyond the work spindle andcan be treated by any one of several tools mounted on three cross slides18, 20, 22 shown in FIG. 2. The cross slides 18, 20 are mounted on thebase 12 substantially diametrically opposite each other (in nineandthree-oclock positions) and can be fed radially toward the axis of thework spindle 16. The third cross slide 22 is mounted at or close to theelevenoclock position, as viewed in FIG. 2, and can also move its toolor tools radially toward the axis of the work spindle 16 whereby thetools which are carried by the cross slide 22 and/or the cross slides18, 20 remove material from the workpiece while the spindle 16 rotates.Such turning operation renders it possible to machine selected surfacesof the workpiece with a high degree of precision. One of the toolscarried by one of the slides 18, 20, 22 is a cutting off or parting toolwhich can separate a finished workpiece 65 from the remaining portion ofthe bar in the work spindle 16 so that the bar canbe moved lengthwise tothus place its front end portion into the range of tools on the crossslides. The tools are mounted in suitable holders of the cross slides18, 20, 22 in a well known manner, not shown. The drive means for thework spindle 16 includes an electric motor 24 a portion of which isshown in the lower left-hand portion of FIG. 1 and a suitabletransmission which is mounted in the frame 10. The feeding and clampingmechanism for the bar is shown in FIG. 3, as at 26. This mechanism ismounted in the base 12 and is movable along a guide rail 28 which isparallel to the axis of the work spindle 16. The means for moving thefeeding and clamping mechanism 26 with reference to the guide rail 28comprises a twoarmed lever 31 having a-first or upper arm 30 coupled tothe mechanism 26 and a second or lower arm 32 provided with a followerextending into the circumferential groove of a cylinder cam 34. The cam34 can be rotated in response to engagement of a clutch 83 having anoutput member provided with a gear which meshes with a gear 40 of thecam 34. The clutch 83 is mounted on an auxiliary control shaft 85 whichis driven by a motor 41 by way of a gear train 37, 39. The auxiliarycontrol shaft 85 further drives a shaft 86 by way of bevel gears 84. Theshaft 86 drives a further shaft 44 by way of exchangeable gears 88, 90,48, 46. The gears 90 and 48 are mounted on an intermediate shaft 50which is parallel with the shafts 86, 44 and normal to theauxiliary'control shaft 85. The gears 46, 48, 90, 88 determine theduration of treatment of workpieces. The shaft 44 drives two controlshafts 36,52. The shaft 36 can be rotated by a gear 38 which meshes witha worm 42 on the shaft 44. The other shaft 52 can be rotated by a gear53 which meshes with a second worm 51 on the shaft 44. The shaft 52 is amain control shaft,

and its function is to control the movements of cross slides 18, 20 and22. To this end, the main control shaft 52 comprises three cams 54, onefor each of the cross slides 18, 20, 22, each of which cooperates with aroller follower on one of three discrete levers 56. Each lever 56 is atwo-armed lever one arm of which is provided with the just mentionedfollower for the associated cam 54 and the other arm of which isprovided with a gear segment 58 meshing with a toothed rack 59 on thecorresponding cross slide 18, 20 or 22 (see the right-hand portion ofFIG. 3).

As shown in FIG. 1, the work spindle 16 is further associated with atool turret 61 which has a set of equidistant radially extending toolholders and is movable axially of the work spindle 16 so that a selectedtool thereon can treat the front face of a workpiece in the clamping andfeeding mechanism 26. The housing 60 for the turret 61 is reciprocablealong ways provided therefor on the base 12. The mechanism which canindex the turret 61 and can move the housing 60 axially of the workspindle 61 is known and therefore not shown in the drawing. If desiredor necessary, one of the cross slides 18, 20, 22 and/or the turret 61can be replaced with a rotary tool spindle, not shown.

The heretofore described parts of the turning machine form a firstturning unit 15 which can be used to treat the peripheral surface andthe front end face of a workpiece while such workpiece is held by themechanism 26 and rotates with the work spindle 16. In addition to thefirst turning unit 15, the turning machine further comprises a secondturning unit which is designated by the reference character 62 andcomprises an indexible carrier or turret 64 for a set of equidistantworkpieces 65. To this end, the periphery of the carrier 64 is providedwith pairs of equidistant work engaging claws or jaws 66, 68, forexample, with a total of eight pairs of such jaws. A suitable actuatingmechanism (not shown) of any known design is provided to move the jaws66, 68 toward their operative or closed and inoperative or openpositions at predetermined intervals so that finished articles 165 canbe released at an evacuating station 150 (FIGS. 2 and 4), that freshworkpieces 65 can be introduced at areceiving station 136, and

that the workpieces 65 can be treated by tools at one or more of theworking stations I, II, III, IV, V, VI located between the stations 136and 150. The just discussed actuating mechanism for the jaws 66, 68 maybe of the mechanical, electromechanical or fluid-operated type.

FIGS. 2 and 3 show that the carrier 64 is indexible about a horizontalaxis which is parallel with and located at a level above the axis of thework spindle 16. Furthermore, the axis of the carrier 64 is laterallyoffset with reference to the axis of the work spindle 16. FIG. 3also-shows that the carrier 64 is supported by a second portion 70 ofthe frame 10 which is mounted on top of the portion or base 12. Theturning unit 62 comprises means for releasably locking the carrier 64 inselected angular positions, namely, in those positions in whichsuccessive pairs of jaws 66, 68 dwell at the stations 150, 136 and theworking stations I to VI. The

' shaft of the carrier 64 is shown at 72, and this shaft carries aGeneva wheel 74 having eight radially inwardly extending slots 75 forthe pin of a driver wheel 78 which is rotatable by a shaft 76. TheGeneva wheel 74 is mounted at the rear end of the shaft 72, namely atthat end which is remote from the working stations I VI and the stations136, 150. In response to each revolution of the driver wheel 78, the pin80 causes the Geneva wheel 74 to turn through 45 degrees which is theangular distance between successive stations in the turning unit 62. Thedriver wheel 78 can be rotated by a gear, pulley or sprocket wheel 82which is mounted in the interior of the base 12 and can receive torquefrom the clutch 83. The means for transmitting torque from the member 82to the wheel 78 comprises an endless flexible belt (e.g., a toothedbelt) or chain 92. The arrangement is such that the driver wheel 78 iscaused to complete one full revolution in response to each engagement ofthe clutch 83.

The turning unit 62 further comprises a plurality of material removingassemblies 94 having carriages which are movable radially or inparallelism with the axis of the carrier 64 and can feed tools intoworkpieces 65 at the respective working stations. In the illustratedturning unit 62, there are provided two assemblies 94 which employangular brackets 96, 98 for radially movable carriages and severalassemblies 94 which are disposed in part at the opposite axial ends ofthe carrier 64 and include carriages movable in parallelism with theaxis of the carrier to remove material at the respective ends ofworkpieces 65 held by the corresponding jaws 66, 68. As clearly shown inFIG. 1, the axial length of the carrier 64 is very small so that arelatively short workpiece 65 can be grasped by the jaws 66, 68 midwaybetween its ends and is exposed at both ends for treatment by theadjoining assemblies 94. The rear assembly or assemblies 94 (includingthe left-hand assembly 94 of FIG. 1) are mounted on the base 12. Theremaining assemblies 94 are mounted on a frame member 100 located infront of the carrier 64. Each of the assemblies 94 comprises a toolspindle 102 which is rotatable by a discrete electric motor 104 throughthe intermediary of a transmission not shown. It is clear that the toolspindles 102 of one or more assemblies 94 may make with the axis of theworkpiece 65 at the respective one of the working stations I to V] anacute angle or an obtuse angle, depending on the nature of work which isto be performed by the tools in the tool spindies.

The control aggregate 106 which regulates the rapid advance and feedmovements of tools which are mounted in the tool spindles 102 of theassemblies 94 is mounted on the frame adjacent to the base 12. Theassemblies 94 are preferably designed in such a way that the movementsof respective tools radially or axially of the carrier 64 are effectedby means of a pressurized fluid, e.g., oil. Therefore, each assembly 94comprises a hydraulic cylinder 108 (see FIG. 3) which is connected withthe aggregate 106 by a hose 1 10. The aggregate 106 comprises a controlcylinder 112 for each assembly 94, and each cylinder 112 is connectedwith the respective hose 110. The pistons 114 of the control cylinders112 are articulately coupled with levers 118 by way of links 116, andthe levers 118 have roller followers 120 which track discrete cams 124mounted on a camshaft 122. The camshaft 122 can be driven by a sprocketwheel 126 through the intermediary of a chain 128 which is furthertrained over a sprocket wheel 130 on the control shaft 36. It is clearthat the chain drive 126, 128, 130 can be replaced by a helt-and-pulleydrive or any other suitable means for transmitting torque from thecontrol shaft 36 to the camshaft 122. The cams 124 are adjustable withreference to the camshaft 122 so that the respective pistons 1 14 can bedisplaced in a predetermined sequence and perform working and returnstrokes of predetermined length. This enables the operators to insurethat the tools mounted in the tool spindles 102 of the assemblies 94will treat the workpieces'65 at the respective stations of the turningunit 62 in a desired sequence. Depending on the nature of the workpieces65 and on the intended final shape 165 of such workpieces, each thereofcan be treated by one or more tools at the front side of the carrier 64as well as by one or more tools at the rear side of the carrier.Furthermore, any given workpiece 65 can be treated simultaneously by twotools, i.e., by tools located at the opposite sides of the carrier 64.

In the illustrated embodiment of the turning machine, the two turningunits 15 and 62 are operatively connected or coupled with each other bymeans of a transfer device 132 which is designed to transport workpieces65 from the work spindle 16 into the spaces between the jaws 66, 68dwelling at or moving toward the receiving station 136. The transferdevice 132 is mounted on a projection 134 of the base 12 and can beactuated by a pressurized fluid, e.g. oil. This transfer devicecomprises a single arm 133 which ispivotable about a horizontal axis(see the pivot 141) extending in parallelism with the axes of the workspindle 16 and carrier 64. When a cutting off or parting tool (e.g., atool in the cross slide 22) has separated a workpiece 65 from the barwhich extends through the work spindle 16, the arm 133 of the transferdevice 132 engages and moves such workpiece from the work spindle to thereceiving station 136 for delivery into the space between the adjoiningjaws 66, 68 which are then held in their open positions. As shown inFIGS. 4 and 5, the free or lower end of the arm 133 of the transferdevice 132 is provided with a work engaging transfer element in the formof a sleeve 138 which can engage a workpiece 65 at the adjacent end ofthe work spindle 16. The sleeve 138 is mounted on a piston rod which isconnected with the piston of a cylinder 139 of the arm 133. The cylinder139 for the piston which is connected with the piston rod 140 ispreferably actuated by a pressurized hydraulic fluid. In one endposition of the transfer device 132, the gripping sleeve 138 is locatedin front of and in axial alignment with the workpiece 65 in the workspindle 16. The internal diameter of the sleeve 138 equals or closelyapproximates the external diameter of the workpiece 65 in the spindle 16so that the sleeve 138 can be pushed onto and thereupon retains suchworkpiece as soon as the latter is separated from the bar in the spindle16. The arrangement is such that, in order to move the sleeve 138 intoor from register with the work spindle 16, the cylinder 139 of the arm133 cams the piston rod 140 to move radially of the pivot 141. Thesleeve 138 accommodates a reciprocable pusher 142 which is biased to afront end position by a helical spring 144. The shank 145 of the pusher142 extends forwardly beyond the sleeve 138 and constitutes a followerwhich tracks the arcuate face of a stationary cam 146 when the transferdevice 132 turns about the axis of the pivot 141 so as to move theworkpiece 65 in the sleeve 138 toward the receiving station 136. Theshank or follower 145 of the pusher 142 registers with the cam 146 whenthe arm 133 isshortened, i.e., when the piston rod 140 is retracted intothe cylinder 139. When the sleeve 138 approaches or reaches thereceiving station 136, the cam 146 causes the pusher 140 to partiallyexpel the workpiece 65 from the sleeve 138 whereby one axial end of theworkpiece abuts against a stop 148 on the transfer device 132. When itassumes such axial position, the workpiece 65 enters into the spacebetween the adjoining jaws 66, 68 at the receiving station 136 by movingradially of the carrier 64. The jaws 66, 68 are thereupon caused toclose and to safely grip'the workpiece 65. The sleeve 138 is thenslipped off the thus gripped workpiece 65 between the jaws 66, 68 andthe transfer device 132 is ready to return to the solid-line position ofFIG. 4. The carrier 64 is thereupon indexed to advance the workpiece 65from the receiving station 136 into register with the tool or toolsworking at the first working station I, thereupon at the station II, andso on toward the evacuating station 150.

The controls for the tools which treat workpieces in the spindle 16 areassociated with the indexing mechanism for the carrier 64 in such a waythat the latter can be indexed through 45 degrees only upon completedtransport of a workpiece 65 by the transfer device 132. In other words,the carrier 64 can be indexed only upon completion of treatment of aworkpiece in the spindle 16. This is achieved due to the fact that theindexing mechanism for the carrier 64 receives motion from the clutch 83for the work spindle 16. As mentioned before, the indexing mechanismincludes the Geneva wheel 74 on the shaft 72 of the carrier 64 and thedriver wheel 78 mounted on the shaft 76 and having the pin 80 which canturn the Geneva wheel 74 and hence the carrier 64 during a certain stageof a full revolution of the driver wheel 78. The latter is driven by theclutch 83. The clutch 83 controls the mechanism 26 for feeding the barin the work spindle 16 and for clamping the bar upon completion of suchlengthwise movement which is necessary to expose the front end of thebar for conversion into a workpiece 65. The clutch 83 is engaged uponcompletion of a workpiece 65 in the spindle 16 and upon completedtransfer of such workpiece to the receiving station 136. The clutch 83then causes the bar in the work spindle 16 to advance lengthwise and theGeneva wheel 74 is caused to turn the shaft 72 of the carrier 64 through45 degrees. Thus, the length of intervals between successive indexingmovements of the carrier 64 depends on the length of intervals which arerequired to form a workpiece 65 and to transfer such workpiece to thereceiving station 136. The length of such intervals is normally lessthan that required for the feeding of rotary tools in the tool spindles102 of the assemblies 94 by the cams 124 on the camshaft 122. Themounting of cams 124 on a single camshaft 122 which is remote from'theassemblies 94 reduces the space requirements of the turning machine, Thecylinders 112 and 108 constitute so-called hydraulic linkages whichestablish operative connections between the camshaft 122 of the controlaggregate 106 and the respective assemblies 94. An advantage of suchhydraulic linkages is that the assemblies 94 can be distributed in theturning unit 62 in any desired way, i.e., any selected assembly 94 canbe shifted from the front side to the rear side of the carrier 64 orvice versa, and any desired assembly 94 can be moved to any one of theworking stations I to VI between the stations 136, 150. A finishedarticle 165 which reaches the evacuating station 150 is removed orejected in response to opening of the respective jaws 66, 68. Thereleased finished article 165 can be caused to descend by gravity into asuitable receptacle, not shown, or onto a suitable take-off conveyor.

Once the carrier 64 is loaded with workpieces 65, a finished article 165is discharged at the evacuating station in response to each indexing ofthe carrier. The precision work is done in the first turning unit 15which includes the work spindle 16, and the operations which can becarried out with a lesser degree of precision are performed in thesecond turning unit 62. It is clear, however, that the transfer device132 can be designed to transport workpieces from the station 136 to thework spindle 16. The working station I (FIG. 4) immediately downstreamof the station 136 is then a receiving station where the blanksrequiring treatment by the tools of assemblies 94 are supplied to thecarrier 64 and the station 150 can accommodate one or more assemblies94. Still further, the persons in charge might wish to operate theturning units 15 and 16 independently of each other; the transfer device132 is then useful as a means for delivering workpieces to the workspindle 16 or for delivering workpieces from a magazine to the receivingstation 136. Alternatively, the transfer device 132 can be used toremove workpieces 65 from the work spindle 166 for delivery to amagazine from which a second transfer device removes workpieces 65 fordelivery to the carrier 64. Such mode of operation will be selected ifthe turning unit 62 is set up to process the workpieces 65 at a rateexceeding the rate of delivery of workpieces 65 from the work spindle16. Thus, once the just mentioned magazine contains a certain supply ofworkpieces 65, the turning unit 62 can be operated at a high speed whilethe first unit 15 including the spindle 16 turns out workpieces at thenormal rate whereby the rapid operation of unit 62 can last as long asthe magazine contains one or more workpieces 65.

The improved turning machine can be used with particular advantage forthe production of articles whose treatment must be carried out in asubstantial number of stages and wherein certain operations must beperformedwith a much higher degree of precision than the remainingoperation or operations. Thus, all precision treatments can be carriedout while a workpiece rotates with the work spindle 16 of the first unit15 and all other treatments can be carried out while the workpiece 65 isheld by a pair of jaws 66, 68 on the carrier 64. In other words, thefirst unit 15 treats a single work piece at'a time but the second unit62 iscapable of treating several workpieces during each period of dwellof the carrier 64. It is clear that the treatment to which theworkpieces are subjected by the tools of the assemblies 94 is also aprecision treatment; however, at least some of these tools might not berequired to remove material with the same degree of precision as thetools in the cross spindles 18, 20, 22 and/or the tools in the turret61.

When the control means shown in FIG. 3 synchronizes the operation of thefirst unit 15 including the work spindle 16 with the operation of thesecond unit 62, the length of intervals during which the carrier 64dwells between successive indexing movements is normally determined bythe first unit 15, i.e., by the length of the interval which is requiredto convert a piece of bar into a workpiece 65. Such interval is normallylonger than the interval required by any one of the assemblies 94 tocomplete the treatment of a workpiece 65 which is held by the jaws 66,68 at the respective one of the working stations 1 to V1. The featurethat the axis of the carrier 64 is parallel with the axis of the workspindle 16 allows for a simplification of the transfer device 132because the latter is merely required to pivot about an axis (of themember 141) which is parallel with the axes of the parts 16, 64 and tomove the sleeve 138 radially and axially, i.e., in parallelism with theaxes of the parts 62, 16 and radially of the pivot 141. The receivingstation of the second turning unit 62 is that (selected) station whichis nearest to the work spindle 16. This insures that the sleeve 138 mustcover a relatively short distance in order to transport a freshly formedworkpiece 65 from the work spindle 16 to the receiving station 136.

It is also clear that the illustrated transfer device 132 constitutesbut one of a large number of transfer means which can be utilized in theimproved turning machine for the transport of workpieces between theturning units and 62. The same holds true for the design of the carrier64. It was found that the transfer device 132 exhibits a number ofimportant advantages, particularly as concerns its compactness (spacerequirements), its initial and maintenance cost, and the accuracy ofwork transfer between the work spindle 16 and the receiving station 136.The single arm 133 of the transfer device 132 occupies little room sothat, when it moves the sleeve 138 into register with the work spindle16 of the first turning unit 15, the single arm 133 is not likely tointerfere with movements of tools on the cross slide 18, 20 and/or 22.This is particularly important when the cross slides are fed one afterthe other and when one of these slides is caused to move relative to thework spindle 16 at the time when the sleeve 138 is about to engage withand remove a freshly formed workpiece 65. As best shown in FIG. 2, thecylinder 139 of the arm 133 can cause the piston rod 140 to move thesleeve 138 downwardly toward a position of registry with the workspindle 16 and thereupon upwardly to entrain the freshly separatedworkpiece 65 and to move the follower 145 into register with the cam 146prior to pivotal movement of the arm 133 to the phantom-line endposition of FIG. 4.

It is also within the purview of the present invention to construct theturning units 15 and 62 in the form of two discrete modules which can beused independently of each other or combined to form the improvedturning machine. Thus, the module which constitutes the turning unit 15can be used independently of the module which constitutes the turningunit 62, and vice versa. The control systemlsee FIG. 3) which cansynchronize the operation of the turning unit 15 with that of theturning unit 62 is then also composed of two or more modules which canbe rapidlyassembled or dis mantled, depending upon whether the two unitsare to be used together or independently of each other.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can, by applying current knowledge,readily adapt it for various applications without omitting featureswhich fairly constitute essential characteristics of the generic andspecific aspects of our contribution to the art and, therefore, suchadaptations should and are intended to be comprehended within themeaning and range of equivalence of the claims.

What is claimed as new and desired to be protected by Letters Patent isset forth in the appended claims:

1. In a turning machine, a combination comprising a first unit having arotary work spindleand at least one tool supporting slide cooperatingwith said spindle so that a workpiece held and rotated by said spindlecan be treated by a tool on said slide; a second unit having a carrierfor a plurality of equidistant work engaging means, means for indexingsaid carrier so as to move workpieces held by said work engaging meansbetween a plurality of stations, and at least one tool support assemblyprovided at least at one of said stations and cooperating with saidcarrierso that a tool held by such assembly can treat a workpiece heldby said work engaging means at said one station; and transfer meansoperative to transport workpieces between said spindle and a selectedone of said stations, said transfer means comprising an arm which ispivotable about an axis parallel to that of said spindle, a workengaging transfer element carried by said arm, and means for moving saidtransfer element in longitudinal direction of said arm and in the radialdirection of said spindle to move said work engaging transfer elementbetween two end positions, in one of which it registers with saidspindle and in the other of which with said selected station.

2. A combination as defined in claim 1, further comprising control meansfor synchronizing the operation of said first unit with the operation ofsaid second unit.

3. A combination as defined in claim 1, wherein said carrier isindexible about an axis which is parallel with the axis of said spindle.

4. A combination as defined in claim 1, wherein said selected station isnearer to said spindle than the other stations.

5. A combination as defined in claim 1, wherein said arm is arranged totransfer workpieces from said spindle to said selected station.

6. A combination as defined in claim 1, wherein said transfer element isarranged to receive a workpiece from said spindle and to transfer suchworkpiece to work engaging means at said selected station, said transfermeans further comprising means for expelling a portion of the workpiecefrom said transfer element during movement of said arm from said onetoward said other end position.

7. A combination as defined in claim 1, wherein said means for movingsaid transfer element in longitudinal direction of said arm comprisescylinder and piston means mounted on said arm and comprising a pistonrod carrying on a free end thereof said transfer element. v

8. A combination as defined in claim 6, wherein said transfer element isa sleeve.

9. A combination'as defined in claim 8, wherein said expelling meanscomprises a pusher which is reciprocably received in said sleeveandcomprises follower means extending from said sleeve, and stationary cammeans adjacent to the path of movement of said sleeve while said armmoves between said end positions to thereby shift said pusher in saidsleeve by way of said follower means. I

10. A combination as defined in claim 1, wherein the workpiece in saidspindle constitutes one end of a bar which is movable axially of saidspindle, and further comprising control means for effecting a lengthwisemovement of such bar with reference to said spindle simultaneously withactuation of said indexing means.

11. A combination as defined in claim 10, wherein said control meanscomprises clutch means and a mechanism for feeding the bar axially ofsaid spindle and for clamping the bar during treatment by the toolcarried by said slide.

12. A combination as defined in claim 1, wherein said second unitcomprises a plurality of tool supporting assemblies each of whichincludes a rotary tool spindle.

13. A combination as defined in claim 1, wherein said first unit furthercomprises an indexible turret for tools and means for moving said turretwith reference to said work spindle so that a workpiece rotating withsaid

1. In a turning machine, a combination comprising a first unit having arotary work spindle and at least one tool supporting slide cooperatingwith said spindle so that a workpiece held and rotated by said spindlecan be treated by a tool on said slide; a second unit having a carrierfor a plurality of equidistant work engaging means, means for indexingsaid carrier so as to move workpieces held by said work engaging meansbetween a plurality of stations, and at least one tool support assemblyprovided at least at one of said stations and cooperating with saidcarrier so that a tool held by such assembly can treat a workpiece heldby said work engaging means at said one station; and transfer meansoperative to transport workpieces between said spindle and a selectedone of said stations, said transfer means comprising an arm which ispivotable about an axis parallel to that of said spindle, a workengaging transfer element carried by said arm, and means for moving saidtransfer element in longitudinal direction of said arm and in the radialdirection of said spindle to move said work engaging transfer elementbetween two end positions, in one of which it registers with saidspindle and in the other of which with said selected station.
 2. Acombination as defined in claim 1, further comprising control means forsynchronizing the operation of said first unit with the operation ofsaid second unit.
 3. A combination as defined in claim 1, wherein saidcarrier is indexible about an axis which is parallel with the axis ofsaid spindle.
 4. A combination as defined in claim 1, wherein saidselected station is nearer to said spindle than the other stations.
 5. Acombination as defined in claim 1, wherein said arm is arranged totransfer workpieces from said spindle to said selected station.
 6. Acombination as defined in claim 1, wherein said transfer element isarranged to receive a workpiece from said spindle and to transfer suchworkpiece to work engaging means at said selected station, said transfermeans further comprising means for expelling a portion of the workpiecefrom said transfer element during movement of said arm from said onetoward said other end position.
 7. A combination as defined in claim 1,wherein said means for moving said transfer element in longitudinaldirection of said arm comprises cylinder and piston means mounted onsaid arm and comprising a piston rod carrying on a free end thereof saidtransfer element.
 8. A combination as defined in claim 6, wherein saidtransfer element is a sleeve.
 9. A combination as defined in claim 8,wherein said expelling means comprises a pusher which is reciprocablyreceived in said sleeve and comprises follower means extending from saidsleeve, and stationary cam means adjacent to the path of movement ofsaid sleeve while said arm moves between said end positions to therebyshift said pusher in said sleeve by way of said follower means.
 10. Acombination as defined in claim 1, wherein the workpiece in sAid spindleconstitutes one end of a bar which is movable axially of said spindle,and further comprising control means for effecting a lengthwise movementof such bar with reference to said spindle simultaneously with actuationof said indexing means.
 11. A combination as defined in claim 10,wherein said control means comprises clutch means and a mechanism forfeeding the bar axially of said spindle and for clamping the bar duringtreatment by the tool carried by said slide.
 12. A combination asdefined in claim 1, wherein said second unit comprises a plurality oftool supporting assemblies each of which includes a rotary tool spindle.13. A combination as defined in claim 1, wherein said first unit furthercomprises an indexible turret for tools and means for moving said turretwith reference to said work spindle so that a workpiece rotating withsaid spindle can be treated by a tool of said turret.
 14. A combinationas defined in claim 1, wherein said second unit comprises a plurality oftool supporting assemblies including two assemblies located at a commonstation.
 15. A combination as defined in claim 14, wherein said workengaging means are arranged to expose two axial ends of workpieces whichare held thereby and the tools of said two assemblies are arranged totreat the opposite ends of workpieces at said common station.